1. Field of the Invention
The present invention relates to rolling element bearings, and more specifically to a high temperature damper for the rolling element bearing.
2. Description of the Related Art including information disclosed under 37 CFR 1.97 and 1.98
There is a need in the prior art of bearings that are used in high temperature environments and that require long shelf lives for a bearing damper that will provide adequate damping for the bearing that will also withstand high temperatures and in which the damping material will not seriously degrade over long periods of time.
U.S. Pat. No. 5,452,957 issued to Duggan on Sep. 26, 1995 discloses a CENTER BEARING ASSEMBLY INCLUDING SUPPORT MEMBER CONTAINING RHEOLOGICAL FLUID for damping a radial ball bearing. The damping fluid is contained in an elastomeric chamber which would not be capable of use in a high temperature environment because the chamber would melt.
U.S. Pat. No. 4,867,655 issued to Barbic et al on Sep. 19, 1989 discloses a VARIABLE STIFFNESS OIL FILM DAMPER in which a bearing is supported by an oil squeeze film damper. An oil chamber is formed by elastomeric seals. The Barbic invention would not be capable of use in high temperature environments because the oil would vaporize. Also, the Barbic invention would not have a long shelf life because the oil could leak out from the damping chamber or the seals could oxidize due to age.
U.S. Pat. No. 5,026,721 issued to Chiba on Nov. 5, 1991 discloses a ROLLING BEARING WITH SLEEVE in which a synthetic resin spacer is used to provide bearing damping. The resin spacer is not capable of being used in high temperature environments because it would melt.
U.S. Pat. No. 6,007,252 issued to Thelen et al on Dec. 28, 1999 discloses a SUPPORT STRUCTURE WITH A VIBRATION DAMPER FOR ROTATABLY HOLDING A ROTATABLE BODY in which the vibration damper is an elastomeric element such as a metal rubber composite element. The metal is a solid and the rubber would not be capable of use in high temperature environments because rubber would melt.
U.S. Pat. No. 6,540,407 issued to Van Dine et al on Apr. 1, 2003 discloses a ROLLING ELEMENT BEARING ARRANGEMENT is which a vibration inhibiting outer ring member may contain a heavy metal such as tungsten. The heavy metal damper ring is a solid metal and not a liquid metal.
U.S. Pat. No. 5,044,789 issued to Damon et al on Sep. 3, 1991 discloses a ROLLER AND BALL BEARING ISOLATOR uses a steel radial wave spring to provide damping. The steel will withstand high temperature environments and have a long shelf life, but is not a liquid. It is also based on coulomb frication damping, which is not as desirable or advantageous as liquid viscous fluid-film damping.
U.S. Pat. No. 5,071,262 issued to Monzel et al on Dec. 10, 1991 discloses a SQUEEZE FILM DAMPER FLUID CONTROL device in which a damping space is filled with oil, and includes an oil inlet passage to provide a pressure to the oil in the space. The space in this invention is not a closed space because of the oil inlet passage, and therefore the damper can leak over time and, therefore, does not have a long shelf life. Also, the oil will evaporate, coke, and possibly ignite in a high temperature environment.
U.S. Pat. No. 5,052,828 issued to Ciokajlo et al on Oct. 1, 1991 entitled BEARING ASSEMBLY FOR USE IN HIGH TEMPERATURE OPERATING ENVIRONMENT and U.S. Pat. No. 5,205,384 issued to Heshmat on Apr. 27, 1993 entitled PODER-LUBRICATED DAMPER WITH WAVY DAMPER PADS both show bearing dampers for use in high temperature environments that also appear to have a long shelf life. However, they do not include a liquid metal as the damping material.
It is an object of the present invention to provide for a bearing damper that provides the desirable and advantageous fluid-film viscous damping and that can be used in an extremely high temperature environment.
It is another object of the present invention to provide for a bearing damper that will have a long shelf life.